Today I have DELL 'mfg' and I have 'make' as Precision workstation 650, precision workstation 610, precision work station 530..

i have 2 combo boxes: 'Mfg' and 'Make'.. the moment I choose DELL as mfg from the first combo box..i get the PWS 650, PWS 610 and PWS 530 in the Make combobox.

currently i am using the selected index changed function for the combobox.. to let his happen..( i mean hard coded )

What If i get a new make called precision workstation 550.. how do I make the combo box add it to the make automatically from the database ? (because..i want to avoid hard coding )

You should use a connection and a query to find all the models of a particular make, then populate the model combobox on the closeup or indexchanged event on the make combobox.